In this mission it's the purpose to steal a dossier of a DEA agent who wants to hand it over to a FBI agent in Las Venturas.

Go to Aldea Malvada and start to shoot every FBI agent. The suspect will run off in a Maverick, step in the other Maverick and follow him. He will also fly above Area 69 where you can follow him, the SAM-sites won't fire at you. But if you fly too low you'll risk a five star wanted level and Hydra will come to chase you. So fly quickly and not too low over Area 69. After the suspect has landed on the helicopter platform of Emerald Isle he will flee into the parking garage and drive away in a Buffalo. Eventually he'll drive in an underground parking garage in Roca Escalante, where a group of FBI agents will be waiting for you next to a couple of Buffalos, kill them first. For that matter you can find a minigun in this underground parking garage. After you killed the suspect and grabbed the suitcase you've passed this mission.

Alternative manner: go to the declared place, sneak along the ridge of the mountain until you can see the suspect. Kill him with a Sniper Rifle, get the suitcase, kill a couple FBI agents and you have obtained the mission!

Hints

When you killed the DEA before he reached his helicopter the FBI agents will try to get away with the suitcase. So make sure to grab the suitcase in time or kill the FBI agents before they can grab it.

When you've obtained all gold medals at the Flight School you can use the Hunter to simplify the mission. When the DEA agent tries to escape with his Maverick you can simply destroy his helicopter with the Hunter, even before he reaches the helicopter platform of Emerald Isle. Use above Area 69 only the minigun of the Hunter, if you use rockets you'll directly get a 5 star wanted level. You can also use the Hunter to kill the DEA even before he reaches his helicopter and the FBI before they can reach the suitcase.

Extra

The DEA agent will use Unique Stunt Jump 31 to leave the parking garage of Emerald Isle and flee to his FBI palls in the underground parking garage of Roca Escalante.